1. Technological Field
The present disclosure relates to managing a global registry of contact information of a communication device, and a method of setting up a call using the global registry of contact information.
2. Description of the Related Art
For many decades, the standard means of real-time, long-distance communication has been the telephone. Almost every individual within an organization has a telephone number which is globally unique and from which an individual may be reached by any telephone world wide.
In more recent years, calls via Internet Protocol (IP) have been gaining prominence, as they have a number of advantages. Some advantages may include that the calls are free at the point of use, can offer better audio fidelity using high-quality audio codecs, and allow video and data sharing as well as voice. Where both circuit switched and packet switched systems are available, packet switched (i.e., IP) calls are generally made in preference to circuit switched (i.e., telephone) calls.
Conventionally, individuals provide their contact information in the form of a telephone number, which is short, globally unique, easy to use, and is usable between organizations which have had no previous contact. However, a telephone number only provides the facility to make voice calls, and at a relatively low quality.
Within a network, many IP setups support ways of mitigating the complexity of making an IP media call (i.e., preconfigured address books on an endpoint let a user call an individual by selecting the individual from a list). In other more sophisticated setups, endpoints register their availability to a central server which can then route calls as well as push out lists of users to the endpoints.
These solutions generally only work within an organization, since they rely on endpoints and servers having the information available to them already. Thus, these solutions only allow individuals to call users whose details are already in the system.
This becomes problematic when an individual wishes to call a user from a different organization, whose details are not already configured on the endpoints and servers. In this situation, the individual needs to know the call protocol and routing information of the organization he or she wishes to call, as well as the identifier which enables the call to be routed to the correct individual within the organization. The caller must also have enough technical understanding to configure his or her endpoint to make such a call. In addition, the servers on both ends of the call must be configured to make and receive calls through a common network, such as the Internet.
If, for some reason, the IP call cannot be successfully made, the caller must resort back to a standard telephone call, which requires a new call attempt to be made, with different contact information (the telephone number) and often on an entirely different device (i.e., a telephone rather than a video endpoint).
Telephone numbers are a long-established method of making telephone calls, which are arranged in a hierarchical fashion, with the world zone the first digit, followed by the country code, the national direct dialing code for regions within the country, and so forth to greater and greater levels of specificity.
FIG. 1 shows an H.323 Global Dialing Scheme (GDS) adopted by some countries, reusing the hierarchical system of telephone calls. FIG. 1 shows a world gatekeeper 100 representing multiple resilient gatekeepers distributed across the world. National gatekeepers, such as, a UK gatekeeper 110, a Netherlands gatekeeper 120, and an Ireland gatekeeper 130 represent single or resilient clusters. Organization gatekeepers, such as, the Swansea University gatekeeper 140, the Edinburgh University gatekeeper 150, the Surfnet gatekeeper 160, the Utrecht University gatekeeper 170, and the HEAnet gatekeeper 180 also represent single or resilient clusters. Endpoints may, in turn, register to the organizations' gatekeepers. The GDS utilizes a hierarchical system of gatekeepers, wherein the prefixes indicate the gatekeeper level in the hierarchy (i.e., “00” indicates the world gatekeeper, “0044” indicates the UK gatekeeper, etc.).
Call protocols (i.e., Session Initiation Protocol (SIP), H.323, or the like) have standard ports (i.e., 5060 for SIP User Datagram Protocol (UDP)/Transmission Control Protocol (TCP), 5061 for SIP Transport Layer Security (TLS), 1720 for H.323, or the like). As long as the organization to be called has used these ports, there is no need for the port to be specified.
Some endpoints (i.e., Tandberg MXP, Tandberg Lifesize, or the like) make multiple connection attempts with different call protocols from the same address (i.e., first SIP is tried, then if not successfully answered, H.323 is tried). As the call attempts are made in sequence, and the later protocols are only tried once the previous have been rejected or timed out, this method has the disadvantages that it can be slow to connect or fail to connect. The method might also not work for all addresses since different protocols use different forms of address (SIP uses a Uniform Resource Identifier (URI) of the form username@hostname, H323 uses a hostname with an optional E164 number, etc).
The Tandberg IP Gateway is a single point of entry for external IP calls, which can be presented with an auto-generated entry screen of options and/or routed using a dial-plan. The Gateway is designed to understand as many protocols as possible so that a user may only have to publish its hostname to be externally contactable.
Domain Name System (DNS) is a long-established system for translating between a globally unique human-readable domain name and an IP address which can be used to contact a service provided on the Internet.
Private Branch Exchange (PBX) systems such as Cisco Call Manager have substantial penetration of business organizations. PBX systems offer the facility to translate from their internal call protocol to standard telephone calls for external calls, as well as being able to make IP calls using protocols such as SIP, by dialing a number into a phone, given the correct configuration.